Big Java example project "hashcode"

You can use this project as follows:

 - invoke the main method of the driver class HashCodeTest by 
 right-clicking on the class representation and selecting the main method.
 - interactive create Coin objects
 - interactively call their hashcode method.
 - inspect and experiment with other methods

Note: Sometimes in BlueJ a dialog (such as input dialog or file chooser)
 appears right at the back of any open windows.  If you cannot see
 a dialog after calling the Driver class main method, minimize any 
 other windows to find the dialog.

This project illustrates concepts covered in Big Java, Chapter 20 
"Advanced Data Structures".

 - to learn about set and map data types
 - to understand the implementation of hash tables
 - to be able to program hash functions
